Generally, it is known that middle distillate fuels such as aviation jet fuels and diesel fuels form gums and deposits on storage, particularly when the storage is at an elevated temperature. These gums and deposits are undesirable because they tend to interfere with the operation of the engine by partially or wholly clogging narrow passageways through which fuels must pass.
Thermal stability is a desired quality in distillate fuels used in jet airplanes and modern diesel vehicles. In the latter instance, the fuel injectors with extremely small idle relief holes need to be kept clean to minimize particulate emissions at idle speed. These idle ports can become plugged, causing rough idling and stalling of the car. The improving of the thermal stability of the distillate fuel would help to avoid such problems.
Thus, it is an object of this invention to improve the thermal stability of diesel fuels and particularly those which are extended with vegetable oil. Other objects will be apparent to those skilled in the art.